Air cleaner



Dec. 23, 1941. W W LOWTHER 2,266,882

AIR CLEANER Filed Sept. 14, 1959 7 v//l/l/I v 279279.] y 37 ---un 4Z ,a 57061721021 MQJ J4( 014/275611 Patented Dec. 23, 1941 UNITED STATES PA'rlizlvlrA or-Flcliz' 2,266,882 Am CLEANER Wilfred W. Lowther, Minneapolis, Minn., assignor, by direct and mesne assignments, of twentyfive per cent to Ruth C. Donaldson, twenty per cent to Robert H. Donaldson, twelve and onehalf per cent to A. Donaldson Olin, six and onef'ourth per cent to Mae D. Buckeye, six and ,one-fourth per cent to Ralph A. Buckeye, twenty-five per cent to Ruth C. Donaldson as trustee, `and five per cent to Donaldson Margaret M.

Application September 194, 19.39, Serial No. 294,886 Claims. (Cl. 18S-15) construction, the fluid level will be maintained My present invention relates to improvements in air cleaners for use in connection with internal combustion engines, and more particularly the invention relates to that 'type of air cleaner wherein the dust laden air is washed or cleansed by means including a body of fluid, usually oil, within the cleaner.

In a more specic sense, the present invention is in the nature of an improvement on the particular air cleaner structure disclosed in my prior Patent No. 1,991,759, of February 19, 1935, en-

of my above identied prior patent is particularly adapted for use in connection with the engines main air intake, the air cleaner of the present invention, while suitable also for this purpose, is particularly adapted and has, as will v'titled Air' cleaner, but whereas the air cleaner that the tractor and automotive industries have long recognized the superiority of the oil washed or fluid containing type for the following reason,

hereinafter appear, certain inherent advantages which render itV particularly suitable for use in cleaning air that is drawn into and through an engines crank case for the purpose of Ventilating Among the important objects of the invention is the provision of an air cleaner of the character described wherein the overall dimensions may be reduced to minimum for any given capacity, while atthe same time maintaining a very high degree of eiciency.

Another important object of the invention is the provision of an improvementin air cleaners of the general character described in which the overall diameter may be reduced over that of to wit: The loil washed type of cleaner requires relatively infrequent servicing and will main-` tain a consistently high degree of elhciency between long spaced service periods without building up any materially increased restriction to air ow; whereas, lter type air cleaners, while capable of relatively high degree of cleaning efficiency Without producing objectionable restriction to air. flow immediately following a servicing period, builds up air flow restriction rapidly under accumulation of dust between service peprevious cleaners of the design, for example, disclosed in my above-identi1ed prior patent,y for any given capacity without producing any reduction of the cleaning eiiiciency.

Arg/other object is the provision of an air cleaner of the so-called oil washed or iluid containing type that can be handled roughly when removed from the engine and disposed at Various abnormal angles such as on its side or even upsideriods and often become almost entirely plugged. Hence, this type of cleaner requires such frequent servicing as to render it undesirable.

While the tractor and automotive industries i recognize the superiority. of the oil washed type of air cleaner and have almost universally adopted the same in preference tothe filter type for use in connection with the engines main air intake and have also recognized the advantages of down without loss of fluid through either the opennlet or outlet.

Another important object of the invention is the provision of an air cleaner structure of the general character-described-which is so shaped and weight balanced that it will not remain disposed on any flat surface in any position wherein the fluid body therein can find its way yto thev inlet or outlet ducts. In this connection it may be specifically stated that the cleaner is prefer-v ably so shaped and balanced that even if placed on a relatively flat support in an upside-down condition, in which position iluid 'would eventually reach the interior of the cleaners outlet in the specific construction illustrated, the cleaner williall on to its side, in which position, due to its the oil washed type of air cleaner over the lter type for use in connection with crank case ventilating systems, they have been forced to use the filter type of lair cleaner in connection with crank case breathing systems by reason of the fact that hitherto available cleaners of the oil wash type would not meet the following noted requirements for a commercially practical crank case' Ventilating system air cleaner, to witz' (a)-4 because the only convenient place'for attachment of an air cleaner to the inlet of a crank cast Ventilating system is usually at the side of an engine where available space is very limited, the.overall dimension of the air cleaner, particu-v llarly the overall diameterthereof, must usually be very small and, in fact,l smaller than most (prior uid containing .air cleaners kof sufficient capacity, (b) because engine crank cases are usually lled with oil through the breather pipe to whiclrithe crank case air cleaner is usually/1 'I attached, such crank case air cleaners must usually be removed each time the crank case is oil serviced, and since most air cleaners of the oil washed or fluid body containing type must be maintained right side up or approximately so to prevent spilling or losing of oil through either the inlet or outlet openings of the cleaner, it hasv been found that hitherto available cleaners of this type are impractical for the reason that service men would usually mishandle such cleaners and thereby lose the body of fluid or sufficient thereof tomaterially seriously reduce the eiciency of the cleaner. In this respect it will .be understood that the usual practice in taking olf the old type cleaners from the breather when servicing the crank case is to lay the cleaner down without regard to its normal right side up position and, of course, this practice if followed by uninformed service station attendants on hitherto available oil washed cleaners of the usual construction, iiuid will be spilled with the result that the efliciency of the cleaner will be impaired.

In the accompanying drawing like characters indicate like parts throughout the several views.

Referring to the drawing:

Fig. 1 is a transverse sectional view through an internal combustion engine incorporating' one of the air cleaners of the present invention applied to the air inlet of the crank case;

Fig. 2 is an enlarged approximately full size sectional view of the crank case air cleaner sectioned on the line 2-2 of Fig. 1; and

Fig. 3 is a sectional view corresponding to Fig. 2 but illustrating the cleaner disposed on its side. The engine herein shown for the purpose of example is of the conventional character such as employed in connection with automobiles, tractors and the like, and includes cylinder block 4 formed with one or more cylinders 5. The cylinder 5 is provided with a piston 6 which connects to the engines crank shaft 'I through the medium of th'e usual connecting rod 8. In accordance with the customary practice, the cylinder block 4 is formed to afford the upper portion of a crank case 9, the lower portion of which is normally closed by a removable bottom pan I0. The particular engine illustrated is of the L-headed type employing conventional poppet valves. The section of Fig. 1 is through the axis of the cylinder and intake valve |I and intake port I2. The stem I3 of the valve I| works axially through aguide I4 and terminates within a valve chamber I5 that is in open communication with the interior of the crank case 9 through an opening or openings I6, and which chamber is normally closed by a removable cover plate I'l. The poppet valve II is operated in the conventional manner from a cam I8 on the engines cam shaft through the medium of reciprocable tappet 20 that engages the lower end of the valve stem I3 within the valve chamber I5. The cylinder head of the engine is indicated as an entirety by 2| and thiscylinder head is formed to afford a combustion chamber 22 projecting 'into which is the electrode end of a. spark plug 23. 'Ilhe intake port I2 connects to and forms a condition of the engines main air and fuel intake duct 24 that is equipped with a conventional carburetor indicated as an entirety by 25. The intake of the carburetor 25 is illustrated as being equipped with an air cleaner 26 which may be assumed to be of the kind disclosed in my prior Patent 2,130,142, of February 13,V 1938, entitled Air What has been hitherto referred to as the engines main intake duct may hereinafter also be referred to as the engines intake manifold, since in multiple cylinder engines the lower portion of this duct is branched out to distribute to the several cylinders. The crank case ventilating system of which the air cleaner of this invention is illustrated as forming part, comprises the crank case breather or oil filler pipe 21 which forms the air intake to the crank case and which is illustrated as being equipped with its outer end with one of the air cleaners of the instant invention, and an air outlet conduit 28 l extending from the valve chamber I5, which in reality`constitutes the upper extremity of the crank case, to the engines main a-ir intake duct or manifold 24. Connection of the duct 28 to the' valve chamber I5 is shown asbeing made through the removable cover plate I1. Preferably and as illustrated, this outlet duct 28 is shown as being equipped with an enlarged portion indicated by 29 which may be assumed to be the casing of a metering valve of the kind disclosed and claimed in my copending application S. N. 294,391, entitled Crank c'ase breathing system. However, an understanding of this valve is not necessary to satisfactorily understand the instant invention and therefore insofar as the instant invention is concerned, this device 29 can be ignored and the conduit 28 simply considered as providing suitably restricted communication between the engines main intake duct and the crank case.

Of course, the purpose of a crank case ventilating system is to provide for withdrawing blowby gases leaking past the piston as fast as they accumulate in the crank case. and before condensation takes place, and in addition to this to maintain a steady flow of fresh air into and through the crank case.

In accordance with the present example this is accomplished by virtue of the low pressure or partial vacuum condition existing in the engines intake duct under engine operating conditions, which causes a constant ow of gases from the crank case through conduit 28 to the engines intake duct 24. As previously indicated, this flow through the duct 28 will cause, in addition to such gases as leak into the crank case by the piston 6, a steady stream of fresh air entering the crank case through the breather pipe 21 and the air cleaners provided at the projected end thereof.

The air cleaner of the invention includes a shell or casing made up of an inverted cupshaped upper section 30 having telescopically applied to the upper end portion thereof a cuplike oil well 3 I The upper shell section 30 preferably and as illustrated is formed of two parts rolled or otherwise secured together and forming at their point of jointure a radially projecting annular rib or flange 32, which forms a stop for telescopic application of the oil well acting lower section' 3|. The upper and lower section 30 and 3| may be secured against accidental separation in any suitable manner, but-this is illustrated as being accomplished by means of a suitable clamping band 33. In order to permit radial compression of the upper edge of the oil well forming bottom section 3| against the telescopically engagedlower portion of section 30, the upper edge of said section 3| is provided with a series of circumferentially spaced slits 34, which, however, extend only partially through the portion of telescopic engagement between the sections 3U and 3l so that they will not interfere with the oil seal between the said sections.-

Extending axially through the shell sections 30 and 3l and rigidly anchored to the upper end of section 30 at 35 is an air 'outlet tube or conduit 36 that is provided in spaced relation to the extreme upper end of section 36 with a plurality of circumferentially spaced ports or apertures 31 that provide nearly complete communication between the interior of the conduit 36 and the interior of the upper shell section.

The bottom of the cup-like section 3l which forms the oil well or fluid receptacle of the device is provided with an air inlet opening of considerably larger diameter than the external diameter of the outlet duct 36, so as to provide an vable manner, but as illustrated, this is accomupper end of the breather pipe 21 by virtue of wedging action resulting from the taper.

' Operation,

'When the cleaner described is in operative position lwith the engine at rest, the uid level will be `substantially as indicated in Fig. 2. Howannular air intake pipe 38 immediately surrounding the duct 36, and which air intake duct 36 is extended to the intermediate portion of the interior of the cleaner shell by means of an upstanding 4annular ilange or sleeve 39 which forms also one of the annular walls of an annular oil receptacle, theouter and bottom walls of which are formed by the cup-like section 3|.

Mounted on the axial air outlet duct 36 above the upper end of the annular ange 39 is a radially projecting and axially depending annular skirt-like Asleeve 4U that serves several important functions, to wit: (a) The annular skirt- I like sleeve 40 forms a reversely and downwardly directed continuation of the annular air intake 38 which terminates approximately at the normal static level of oil y in the annular oil receptacle. (b) The annular skirt-like flange 4l) serves to divide the interior portion of the cleaner shell above the annular oil' receptaclarwhich portion constitutes an expansion chamber, into a highA velocity lower expansion chamber section` 4| radially outward of the vertical wall of the skirt- 4 ever, when the engine is set in operation there will be a continuous but variable ow of air from atmosphere through the cleaner described through the breather pipe 21 to and through the crank case and valve chamber I5 to the engines air to the fuel intake duct 24 through the medium conduit 28 and metering valve housing 29, if such be provided. v

It is, of course, assumed that the crank case is sealed from atmosphere except through the air cleaner described. The 'air thus passed through the crank case air cleaner by virtu'e of the difference between atmospheric pressure and the pressure in the intake duct 24 will impinge upon oil in the oil receptacle immediately below the downwardly directed section of the air .intake passage 38 and will cause a large portion of the oil to be displaced from the annular oil well into the expansion chamber and th'e air Will reverse its direction of travel over such oil as remains in the annular oil receptacle and will pass through the constricted annular passage 444 into the high velocity lower section 4I ofthe expansion chamber. The air will, of course, rapidly expand as it leaves the constricted passage 44 and will become very thoroughly commingled with oil carried therewith into the lower portion of the expansion chamber. While the air will lose considerable velocity after leaving the constricted passage 44 it will, nevertheless, maintain a relatively high ing the same'skirt-like flange 40 serves as an oil directing baille and directsall oil reutrned from the expansion chamber tothe oil well at a point materially below the/upper end of the upwardly directed primary section of the annular'intake passage 38. In other'words, under all conditions `the skirt-acting flange 40 prevents oil from entering the upper opened end of the sleeve 3 9.

Preferably and as illustrated, the entire expansion chamber is packed with a suitable lter material such, for example, as hair or mineral wool, such filter material being indicated by- 43. For

performing the dual function of retaining thevelocity through the lower high velocity section of the expansion chamber and will further' expand over the upper edge of the skirt-like flange 4D as it enters the lower velocity section. A large amount of oil will be carried with the air entirely through the high Velocity lower section of the expansion chamber, but as the air expands above the high velocity lower section, the velocity will be materially decreased and oil carried with the air. will nd its way into the relatively dead air annularconical space surrounding the upper portion of the outlet duct 36 intermediate the radial yportion of the flange 40 and the ports 31. The thoroughly cleaned air will pass through ports 31 into the axial outlet tube 36 to the engines crank case. Of course, a large portion of the dust and all the heavier particles will be removed from the dust laden air entering the cleaner by the process of imping/ement as it reverses its direction of travel over the oil in the well, but such light particles of dust as remain in the air after leaving the oil well will beintercepted by oil inthe lter containing expansion chamber and Will be thereafter returned to the oil well with the oil. The ilter materiaL'which may hereinafter be referred tol as oil and dust intercepting means, serves not only as an oil soaked self-cleaning Y filter but further serves together with the oil to breather pipe 21 or to its equivalent in any suit-v 75 subject the dust to what is referred to as a scrubbingprocess and stillffurther'serves the' important function of interceptingand returning oil to the oil well. As stated before, oil will be collected in this quiet zone above the skirt-like flange 4U and, of course, this hydraulic'head of oil will continuously drain back into the air as it passes through the high velocity lower section of expansion under operating'conditions.

Not only does the skirt-like flange 40 obviously serve to direct oil away from the upper end of the intake tube or sleeve 39 under operating conditions, but it will also be evident that this skirtlike ange will serve this same purpose under any abnormal condition such, for example, as when it is laid on its side as when oil servicing the engine. The static level of the body of oil "J when the cleaner is disposed on its side is illustrated in Fig. 3

The preferred practice in carrying out the invention is to space the holes 3l sufciently far from the normal top of the cleaner that the said holes will be above the oil level in the top of the cleaner when the cleaner is held upside down,

even for a prolonged period. In fact, with the' arrangement illustrated, the fluid body will be spaced from the holes 31 and prevented from entering the tube 36 in any rotated position of the vcleaner. In Figs. 2 and 3 the approximate fluid level in an upside down position of the cleaner is shown by dotted lines Y'.

As previously indicated, the cleaner is so shaped and balanced that it will not remain upside down on any relatively ilat support even if inadvertently placed on the support in that position, but will roll over on to its side where the' fluid will be well spaced from both the inlet and outlet. 'Ihis is 'accomplished largely by virtue of rounding the head and of the shell section 30 and so distributing the weight of the device that it will always roll on to its side under the action of gravity.

Preferably theopen upper end of the intake tube or sleeve 39 is rolled outwardly and downwardly at 39a to provide an oil trap flange which will serve when the cleaner is turned upside down, for example, to trap and prevent oil on the outside surface of the sleeve 39 from running off of the end thereof and on to the radially pro- `ecting portion of the skirt-acting flange 40. This Vis desirable since in the absence of the ange 39a, uid once deposited on the skirt-like element 40 would be apt to drip into the primary vertical portionv of the outlet passage 38, which would not only result in loss of oil but would also result in collection of dust on the inner surface of the sleeve 39 and consequent, at least, partial plugging of that portion of formed thereby.

What I claim is:

1. An air cleaner including a cylindrical shelllike casing formed by an inverted cup-like main upper section and an oil well 4forming cup-like lower section, an opening in the bottom of the lower section, an air admission sleeve extending from the margin of the opening in said lower section upwardly in said casing and having an open upper end spaced substantially above the normal level of oil in said lower section, an annular baffle member including a cylindrical skirt portion radially spaced from said sleeve and a closed horizontal upper endin vertical spa'ced relation to the upper end of the sleeve, the skirt portion of said baille terminating adjacent the normal oil level and forming with said sleeve an air reversing passage, said baule member also forming with the casing a lower, high air velocity chamber and an upper, lower velocity chamber theintake passage 38 in communication therewith, the skirt portion` defining the inner circumferential Wall of the high velocity chamber and the closed upper end forming a bottom wall for the low velocity chamber, a mass of filtering material substantially lling said casing above the oil level therein and extending continuously through said high and low velocity chambers, and an air outlet tube in said casing having an inlet end portion in and embraced by said ltering material` in said low velocity chamber intermediate the upper end of the casing and said closed end of the bafile member and radially inwardly of said skirt portion.

2. The structure defined in claim 1 in which the said shell-like casing is so weighted and the head thereof so formed that the cleaner will roll on to its side when placed on a relatively at support in an upside down position.

3. The structure dened in claim 1, in which the interior of the outlet tube opens into the upper interior portion -of the casing in such spaced relation to the top of the cleaner that such point of opening will remain `spaced from the uid body in all rotated positions of the cleaner.

4. An air cleaner comprising a shell-like casing providing an oil well in its bottom, and an annular expansion chamber above said oil well, an air outlet tube extending from the upper portion of the expansion chamber axially through the bottom of the oil well, an air intake opening in the oil well forming bottom of the cleaner casing, said air 'intake opening being concentric with but of vlarger dameter than the outlet tube so as to form with the outer surface of the intake tube an annular air passage, yan upstanding sleeve extending from said primary annular intake passage to the interior of the casing at a point materially above the normal static uid level in the well, and a baiie flange anchored to the outlet tube, said baille ange comprising a top portion projecting outwardly from the outlet tube at a point above and spaced from the upper end of said sleeve and a depending skirt portion radially outwardly spaced from the upstanding sleeve but radially inwardly spaced from the outer wall of the casing and terminating With its lower edge below the upper end of the upstanding intake sleeve; said skirt forming with the upstanding sleeve a downwardly directed continuation of the upwardly directed intake passage formed by the sleeve, dividing the expansion chamber into a high velocity lower section surrounding the upper portion of the upstanding sleeve and a low velocity upper expansion chamber section overlying the high velocity lower section thereof and the upper end of the intake sleeve, and further serving as a baille for directing oil'from the expansion chamber to a level safely below the upper end of said sleeve, the inner wall of the an-` nular upper section of the expansion chamber being formed by the air outlet tube, said lower and upper sections of the expansion chamber being filled with a lteringmedium.

5. The structure dened in claim 1 in which the interior of the outlet tube opens into the upper interior portion of the casing in such spaced relation to the top of the cleaner that such point of opening will remain spaced from the uid body in all rotated positions of the cleaner, and in which the. said shell-like casing is so weighted and the head thereof is so formed that the cleaner will roll onto its side when placed on a relatively flat support in an upside down position.

` WILFRED W. LOWTHER. 

